Method and apparatus for hermetically sealing packages

ABSTRACT

A method of sealing a comestible article within a heat-fusible bag by advancing the article within the bag past an air pressure device which simultaneously applies air pressure and suction to collapse an open end of the bag, advancing the article past a compression device which further collapses the end of the bag and maintains the end tightly closed, and advancing the article past a heat sealing device which simultaneously fuses the end of the bag and severs a portion of the end therefrom. Suitable apparatus for performing the method includes a conveyor for advancing the article past the air pressure, compression, and heating devices; the air pressure device comprising a blower having an exhaust for applying air pressure to the end of the bag and an intake for producing suction adjacent the end; and, compression and heating devices comprising upper and lower rotatable belts between which the end of the bag is compressed with one pair of downstream pulleys supporting the belts of which one pulley includes an upper heated disc for pressing the end of the bag against a lower disc on the other pully to simultaneously fuse the end of the bag and sever an outer portion therefrom. The heat-fusible bag includes an improved end structure particularly suitable for use with the present invention.

United States Patent [191 Young 1 Oct. 28, 1975 METHOD AND APPARATUS FOR HERMETICALLY SEALING PACKAGES [76] Inventor: John E. Young, 721 Spring Garden Drive, Bluefield, W. Va. 24701 [22] Filed: May 8, 1974 [21] Appl. No.: 468,070

[52] Cl. 53/22 B; 53/79; 53/112 B; 53/372; 53/373 [51] Int. Cl. B65B 31/00; B65B 7/06 [58] Field of Search 53/22 B, 79, 112 B, 372, 53/373 [56] References Cited UNITED STATES PATENTS 2,410,834 11/1946 Messmer 53/112 B X 2,987,107 6/1961 Sylvester et al 53/372 3,019,583 2/1962 Sylvester et al 53/373 3,330,093 7/1967 Schorer 53/189 3,508,379 4/1970 Noyes et al. 53/189 Primary ExaminerTravis S. McGehee Attorney, Agent, or Firm-Walter G. Finch [57] ABSTRACT A method of sealing a comestible article within a heatfusible bag by advancing the article within the bag past an air pressure device which simultaneously applies air pressure and suction to collapse an open end of the bag, advancing the article past a compression device which further collapses the end of the bag and maintains the end tightly closed, and advancing the article past a heat sealing device which simultaneously fuses the end of the bag and severs a portion of the end therefrom. Suitable apparatus for performing the method includes a conveyor for advancing the article past the air pressure, compression, and heating devices; the air pressure device comprising a blower having an exhaust for applying air pressure to the end of the bag and an intake for producing suction adjacent the end; and, compression and heating devices comprising upper and lower rotatable belts between which the end of the bag is compressed with one pair of downstream pulleys supporting the belts of which one pulley includes an upper heated disc for pressing the end of the bag against a lower disc on the other pully to simultaneouslyfuse the end of the bag and sever an outer portion therefrom. The heat-fusible bag includes an improved end structure particularly suitable for use with the present invention.

18 Claims, 4 Drawing Figures U8. Patent Oct. 28, 1975 Sheet 1 of 2 US. Patent Oct.28, 1975 Sheet 2 of2 3,914,917

FIG. 3

FIG. 4

METHOD AND APPARATUS FOR HERMETICALLY SEALING PACKAGES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to foods and beverages and more particularly to processes and apparatus for hermetically sealing packages containing comestible articles.

2. Description of the Prior Art Packaging techniques have been greatly influenced by consumer preference particularly in the packaging of comestible articles such as bread, cakes, candies, and the like which are usually consumed in divided portions of the whole product so that reclosable packages have become quite popular. In addition, consumer preference has led to widespread use of transparent packages to permit inspection of the product prior to purchase. For example, loaves of bread are frequently packaged in tubular polyethylene bags of which one end is permanently sealed and the other is tied in a socalled pony tail by a twisted wire or tie-wrap to permit reclosing the bag as the contents are consumed. Examples of this type are illustrated in Bremkamp US. Pat. No. 3,182,893, Walker US. Pat. No. 3,402,052, Morris US. Pat.- No. 3,428,240, and Weeks US. Pat. No. 3,432,310.

It is nearly always preferable to maintain freshness of the product from the time it is packaged until it is used. The tie-wrapped bag is successful only to a degree in this regard since air inherently leaks into the package through the tie-wrapped end. Another type is illustrated in Smith US. Pat. No. 3,092,502 which uses end seals applied over conventional gusset-folded ends of the package. However, tie-wrapped packages by their very nature do not maintain freshness as well as a package that is hermetically sealed and the reclosable features of gusset-folded and end-sealed packages are often defeated by removal of the seals.

Accordingly, an object of the present invention is to provide methods and apparatus for hermetically sealing comestible articles within a heat-fusible package such as a transparent tubular plastic bag for prolonging freshness of the product therein and to provide a sealed end structure that is easily opened without destroying the closeability characteristics of the package. It is also an object of this invention to provide an improved end structure for heat-fusible plastic bags particularly suited to the methods and apparatus of this invention.

SUMMARY OF THE INVENTION The foregoing and other objects and novel features are generally achieved by the method of subjecting an open end portion of the bag containing the packaged article to air pressure for substantially simultaneously partially evacuating the bag and closing the end portion, further compressing the closed end portion to deplete additional air from within the bag and maintain closure of the end portion, and heating a relatively narrow portion of the closed end portion to fuse opposite sides thereof along a sealing seam and to simultaneously sever an outer portion from the bag.

Suitable apparatus for performing the foregoing method includes a conveyor for advancing the bagged product past a blower which directs air pressure against a top side of the open end portion while applying suction adjacentthe end portion to withdraw air from within the bag, for advancing the bagged product past a compression means including opposed parallel belts which further compress the closed end portion to deplete additional air from within the bag while maintaining closure of the end portion, and for advancing the bagged product past a heat sealing means including a pair of cooperating discs of which one supports the closed end portion and the other is heated and presses the end portion against the support disc to both fuse the opposing sides of the closed end portion and to remove a portion therefrom lying outside the fused area.

The improved end structure includes a tab portion joined to the bottom side of the bag that extends beyond the top and side portions of the bag to aid in filling the bag and thereafter to assist the blower in evacuating the bag and for subsequent gripping by the belts.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing methods and apparatus of the invention will appear more fully from the following detailed description when read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are not intended as a definition of the invention but are for the purpose of illustration only.

In the drawings wherein like parts are marked alike:

FIG. 1 is a perspective view of the apparatus preferred for carrying out the steps of the invention showing bagged articles being serially advanced by a conveyor past an air pressure means, a mechanical pressure means, and a heat sealing and severing means;

FIG. 2 is a perspective view showing a loaf of bread within a transparent plastic bag and illustrating the improved construction of the open end of the bag to be sealed in accordance with the invention;

FIG. 3 is a perspective view of the bagged article of FIG. 2 showing the end portion closed and sealed but with an outer portion or tab still attached; and

FIG. 4 is a perspective view of the bagged article of FIG. 3 showing the tab severed from the bag with the bag in condition for the application of an end closure if desired.

DESCRIPTION OF THE PREFERRED EMBODIMENT For the purpose of illustration, the article to be packaged is shown as a loaf of bread such as in FIG. 2 although the invention can be used for packaging other comestible articles. In accordance with the invention, the loaf B is inserted in a heat-fusible tubular package or bag 10 which already has one of its ends 12 closed and sealed in the conventional manner. The other end is open and remains to be sealed; such end includes opening 14 through which the loaf B has been inserted. The open end preferably includes an elongated tab 16 extending beyond the end of the top and sides of bag 10 as shown in FIG. 2. Tab 16 may include slotted apertures 18 to facilitate insertion of the loaf B in bag 10 by conventional bagging apparatus (not shown).

After the loaf B is bagged as shown in FIG. 2, it is directed, such as by gravity, to the upper right or upstream end of a conveyor assembly 30 as viewed in FIG. 1. The conveyor 30 advances the bagged article, preferably articles in succession, downstream to the left to a packaging station (not shown) where they may be boxed for shipment.

Between the upstream and downstream ends of conveyor 30, the open end of bag is advanced past a blower assembly 40 which initially closes the open end by air pressure and suction to form a closed end portion 20. Thereafter, the closed end portion is advanced past a sealing apparatus generally denoted by numeral 46 which both depletes air from within bag 10 and fuses the top side of closed end portion 20 to the bottom tab portion 16 along a sealing seam 22 (FIG. 3) and simultaneously severs or trims a waste piece 24 along seam 22 as will be explained in greater detail.

Conveyor assembly is preferably constructed as shown in FIG. 3 so as to include an elongated conveyor table 32 along which a pair of laterally spaced conventional conveyor chains 34 are moved by a suitable drive means (not shown) beneath the bags 10 to advance the bags from the upstream to downstream ends of the conveyor 30 past the blower assembly and sealing apparatus 46. Conveyor table 32 includes an upstanding side wall 36 from which a flange 38 extends laterally along the length of table 32 for supporting the tab 16 before it passes the blower assembly 40 and thereafter for supporting the closed end portion 20 between the blower assembly 40 and sealing apparatus 46. The preferred elevation of flange 38 is near the middle of the height of loaf B.

Blower assembly 40 is preferably electrically driven in a conventional manner and includes a blower exhaust duct 42 which directs air pressure from within blower 40 downward against the open top side of bag 10 as it advances past duct 42. The direction of air flow is illustrated by the downward pointing arrows beneath duct 42.

Blower 40 also includes a blower intake duct 44 laterally adjacent to the flange 38 as illustrated in FIG. 1. As bag 10 advances downstream along conveyor 30, the bottom tab 16 is supported by flange 38 and as the open end 14 is advanced past blower 40, the flow of air entering intake duct 44 creates a suction that withdraws some of the air from within the bag 10. This suction pressure is illustrated by the arrows pointing toward intake duct 44. Simultaneously, the air flow directed downward from exhaust duct 42 urges the top side of the open end of bag 10 downward against tab 16 to form closed end portion 20. Part of the air moving downward flows along the top of closed end portion 20 and into the intake 44 to provide make-up air for blower 40 and to maintain contact of the top and bottom sides of closed end 20. Air flowing over the extended tab 16 from the shorter top side of end 20 contributes to the evacuation of air from within bag 10.

Sealing apparatus 46 includes a drive housing 48 positioned alongside conveyor 30 as shown in FIG. 1 upon which are mounted an upper belt 66 and lower belt 68. Lower belt 68 extends around a lower main pulley 54 secured to a shaft 56 extending from housing 48 and around a similarly arranged pulley and shaft upstream therefrom and hidden by table 32, sidewall 36, and flange 38. Upper belt 66 extends around an upper main pulley secured to a shaft 52 extending from housing 48, around an idler wheel 58 secured to a shaft 60 extending from housing 48, and around another idler wheel 62 secured to a shaft 64 extending from housing 68.

The pulley and idler wheels are positioned so that the adjacent flights of belts 66 and 68 extend parallel to each other in substantial alignment with and downstream from flange 38 which is cut away in the area of the upper flight of lower belt 68. Furthermore, idler wheel 62 is positioned below and downstream from idler 58 to form a sloped section 70 in the belt 66 extending between idler wheels 58 and 62. The sloped section 70 provides an entrance nip for entry of closed end 20 of bag 10 between the adjacent flights of belts 66 and 68. These flights further compress closed end portion 20 as it passes therebetween. The extended tab 16 is easily gripped by belts 66 and 68 while the shorter top and sides of end 20 being compressed by the belts results in a tightly wrapped package.

Belts 66 and 68 are moved by rotation of main pulleys 50 and 54 which are in turn rotated from within drive housing 48 by any suitable drive means (not shown) which may include gear wheels linking shafts 52 and 56. Idler shafts 60 and 64, and the hidden idler shaft for lower belt 68, may be mounted for rotation on drive housing 48 or, if desired, may be rigidly secured to the housing with the idler wheels mounted for rotation on the shafts. If desired, the drive means within housing 48 may be used to drive conveyor chains 34 in synchronism with belts 66 and 68 to maintain alignment of the bagged articles on conveyor 30.

A sealing disc 72 is mounted on shaft 52 outboard of upper main pulley 50 and a backing disc 74 is mounted on shaft 56 outboard of lower main pulley 54, both discs being rotated by rotation of shafts 52 and 56. Sealing disc 72 is relatively thin compared to the thickness of backing disc 74, the former being positioned along shaft 52 so as to bear substantially against the middle of backing disc 74, both being positioned to coincide with the sealing seam 22 to be formed in bag 10 as shown in FIG. 3.

The sealing disc 72 is preferably metallic, being heated by a conventional electric heater 76 mounted upon drive housing 48 so as to at least partially surround disc 72 as shown. Heater 76 preferably includes an adjustable thermostat 78' which may be used to select the temperature at which the sealing disc is maintained within selected limits. This permits the disc to be heated at whatever temperature is needed to fuse the meaterial from which bag 10 is made, it being understood that diflerent types of materials may be used for packaging different articles.

The backing disc 74 is preferably made of a heatresistant plastic since it will absorb less heat from sealing disc 72 than would a steel disc thereby preventing possible damage to the underside of closed end portion 20 as it passes over the disc 74. It also provides a somewhat resilient surface against which the heating disc 72 urges tab 16 to sever it from closed end 20.

The outer periphery of sealing disc 72 may be rounded or flat as shown depending on the type of sealing seam 22 that is desired. In addition, its sealing edge may also be alternately raised and relieved around the circumference of the disc to provide an intermittent sealing seam 22 if desired to package articles that may be exposed to ambient air and to provide an even more easily opened package.

It should be understood that the discs 72 and 74 are spaced apart an amount sufficient to permit closed end 20 to pass therebetween but close enough to exert enough pressure on the end 20 to sever the tab portion 16 from the closed end 20 simultaneously with the heat-fusion of the opposite sides of end 20 at the point of tangential contact by discs 72 and 74. The severed tab 16 is carried by belts 66 and 68 beyond pulleys 50 and 54 where it may fall into a receptacle (not shown). If desired, an air flow may be used to blow the severed tab 16 away from conveyor 30 to prevent interference with the bagged articles thereon.

OPERATION In operation, bags with loaves B inserted therein are dropped by conventional feeding means (not shown) onto the upstream end of conveyor 30 which advances them downstream in sequence by conveyor chains 34 as illustrated in FIG. 1. As the bags approach blower 40, the top side of open end 14 of each bag 10 is subjected to positive air pressure from blower exhaust duct 42 and simultaneously to suction pressure by air entering blower intake duct 44. The suction creates a slight vacuum within bag 10 to withdraw air from within the bag which along with the air pressure directed to the top side of the end portion, collapses the end of the bag to form a closed end as shown in FIGS. 1 and 3. The bottom side of closed end 20, including tab 16, is supported on flange 16 at about the middle of the height of bag 10 as the bag continues to advance toward the sealing apparatus 46.

As the bag 10 approaches sealing apparatus 46, the closed end portion 20 enters the nip between the belts formed by sloped section 70 of belt 66 and the top flight of belt 68. The belts 66 and 68 grip closed end 20 and the extended tab 16 to advance the bag 10 in cooperation with conveyor chains 34. Belts 66 and 68 serve to further compress closed end 20 toward the loaf B thereby depleting additional air within the bag so that loaf B is firmly enclosed by bag 10. The belts 66 and 68 maintain closure of closed end portion 10 as the bag advances to the sealing disc 72 and backing disc 74.

As closed end 20 passes between the discs 72 and 74, the heat from disc 72 passes through the upper side of the closed end and fuses it to the lower side along a sealing seam 22 as shown in FIG. 3. The pressure between sealing disc 72 and backing disc 74 is sufficient along with the heat from disc 72 to simultaneously sever the tab 16 along sealing seam 22 as shown in FIG. 4. The severed tab 16 is carried past the pulleys 50 and 54 by belts 66 and 68 where it may fall into a container (not shown) or if desired, it may be blown by air pressure out of the path of advance of bags 10.

The thermostat control 78 may be adjusted as needed to select the temperature needed to maintain sealing disc 72 at a temperature sufficient to fuse closed end 20 and sever tab 16 therefrom.

The bag 10 continues to advance along conveyor to conventional closure apparatus (not shown) which may apply any type of mechanical closure to the sealed end portion 20 such as, for example, a gummed tape or flexible tie strip. If desired, the package may be shipped as is with no further closure being required.

Conveyor 30 preferably advances the bagged articles at a constant rate of speed although they may be advanced intermittently if desired to permit blower 40 to be turned on only after the open end 14 is beneath exhaust duct 42. In this instance, the bags 10 would be spaced along conveyor 30 so that an end portion 20 would not stop between discs 72 and 74 while an end portion is beneath duct 42 to prevent burning of the end portion by disc 72.

Fusing and severing of closed end 20 provides a hermetic seal along sealing seam 22 which may be easily opened by slight pressure without destroying the end of the bag. This permits the consumer to use whatever mechanical closure is provied to repeatedly open and close the bag during periodic consumption of the product. However, prior to such use, the seal prolongs freshness of the bagged product by preventing leakage of air to within the bag. Shelf life is thereby increased and the products, being tightly wrapped, are easily stacked for display. The consumer may easily inspect the product prior to purchase. If desired, inner wrappers may be inserted with the product prior to sealing for advertising the product.

Thus, the invention having being described in its best embodiment and mode of operation, that which is desired to be claimed by Letters Patent is:

1. A method of sealing a comestible article within a subjecting an open end portion of said bag to suction pressure for partially evacuating said bag; directing positive air pressure against an outer portion of said open end portion for collapsing said end portion; compressing said end portion for further depleting air from within said bag and for maintaining closure of said end portion; and

heating a relatively narrow portion of said end portion for substantially simultaneously fusing said closed end portion and severing an outer portion therefrom.

2. The method of claim 1 wherein compressing said end portion comprises the step of:

applying positive pressure to opposite sides of said closed end portion to partially collapse said end portion and maintain said opposite sides in closed position.

3. The method of claim 1 wherein heating said narrow portion comprises the steps of:

supporting one of opposite sides of said end portion;

and

substantially simultaneously applying a heated member to the other of said opposite sides urging said opposite sides together under pressure sufiicient to fuse said opposite sides and to sever an outer portion therefrom.

4. A method of sealing a comestible article within a partially closed heat-fusible bag comprising the steps of:

advancing said article within said bag along a path of advance with an open end portion of said bag advancing along a support means;

applying air pressure against a top portion of said open end portion and substantially simultaneously withdrawing air from within said bag through said end portion to collapse said end portion into closed engagement;

advancing said article with said closed end portion passing between a compression means for further depleting air from within said bag and for maintaining said end portion in closed engagement; and thereafter advancing said article with said closed end portion passing between cooperating portions of a heat sealing means for fusing said closed end portion and for substantially simultaneously severing an outer portion from said fused end portion.

partially closed heat-fusible bag comprising the steps 5. The method of claim 4 wherein advancing said article comprises the steps of:

advancing said article within said bag along a conveyor means and supporting a bottom portion of an open end portion of said bag at a level between top and bottom sides of said article within said bag.

6. The method of claim 4 wherein applying air pressure against atop portion of said open end portion and withdrawing air from within said bag comprises the steps of:

directing a flow of air against said top portion urging said top portion toward a bottom portion of said open end portion and simultaneously directing a flow of air away from said top and bottom portions for drawing said top and bottom portions into closed engagement.

7.. The method of claim 4 wherein advancing said article with said closed end portion passing between a compression means comprises the step of:

advancing said closed end portion between upper and lower flights of a pair of cooperating endless belts for compressing said closed end portion to further deplete the air from within said bag and maintain said end portion in closed engagement.

8. The method of claim 4 wherein advancing said article with said closed end portion passing between cooperating portions of a heat sealing means comprises the step of:

advancing said closed end portion between the outer peripheries of a pair of cooperating sealing discs of which one disc of said pair supports one side of said closed end portion and the other is heated for urging an opposite side of said closed end portion into fused engagement with said one side, said sealing discs simultaneously severing an outer portion of said closed end portion from said bag.

9. The method of claim 4 further including the step of maintaining the temperature of said heat sealing means between selectable limits.

10. Apparatus for sealing a comestible article within a partially closed heat-fusible bag comprising in combination:

air pressure means including a blower having an exhaust structure for directing a flow of air against one of said opposite sides and an intake structure adjacent said open end portion for withdrawing air from within said bag, said exhaust structure and said intake structure cooperatively urging said opposite sides into closed contact;

compression means for receiving said closed end portion and for further compressing said end portion to deplete additional air from within said bag through said end portion while maintaining closed contact thereof; and

heating means for receiving said closed end portion and for substantially simultaneously fusing said opposite sides and severing an outer portion of said end portion from said bag.

11. The apparatus of claim 10 wherein said compression means comprises:

a pair of rotatable endless belt means including opposed parallel flights for receiving said closed end portion and further compressing said end portion to deplete air from within said bag.

12. The apparatus of claim 10 wherein said heating means comprises:

a pair of rotatable disc means one of which is heated for pressing said opposite sides against the other of said disc means to fuse said opposite sides and sever a portion of said end portion from said bag.

13. Apparatus for sealing a comestible article within a partially closed heat-fusible bag comprising in combination:

advancing means for advancing said article within said bag along a path of advance including support means for supporting an open end portion of said bag along said path;

air pressure means adjacent one side of said advancing means for applying air pressure against a top portion of said open end portion and for withdrawing air from within said bag through said end portion to collapse opposite sides of said end portion into closed contact against said support means;

compression means adjacent said one side of said ad vancing means and downstream from said air pressure means for further compressing said opposite sides to deplete additional air from within said bag while maintaining closed contact of said opposite sides of said end portion; and

heat sealing means adjacent said one side of said advancing means and downstream from said compression means for fusing said opposite sides and for simultaneously severing an outer portion of said end portion from said bag.

14. The apparatus of claim 13 wherein said advancing means comprises:

conveyor means movable along said path of advance for moving said article past said air pressure means, said compression means, and said heat sealing means, said support means comprising a flange means extending along one side of said conveyor means for supporting a bottom portion of said open end portion between top and bottom sides of said article within said bag.

15. The apparatus of claim 13 wherein said air pressure means comprises:

blower means including exhaust means overlying said top portion for directing a flow of air against said top portion and intake means laterally adjacent a bottom portion of said open end portion for producing suction within said bag and, together with said flow of air, for urging said top and bottom portions into closed contact.

16. The apparatus of claim 13 wherein said compression means comprises:

a pair of rotatable endless belt means including opposed parallel flights in substantial alignment with said support means for compressing said end portion therebetween to deplete air from within said bag and to maintain said opposite sides in closed contact during advancement of said article to said heat sealing means.

17. The apparatus of claim 13 wherein said heat sealing means comprises:

a pair of rotatable disc means having tangential surfaces in substantial alignment with said end portion along said path of advance, one of said disc means being heated for pressing said opposite sides against the other of said disc means under pressure sufficient to fuse said opposite sides and simultaneously sever an outer portion of said end portion from said bag.

18. The apparatus of claim 13 wherein said compression means and said heating means comprise:

.a pair of rotatable endless belt means including pposed parallel flights in substantial alignment with said support means;

upper pulley means spaced along said path of ad- Vance adjacent said advancing means, one of said belt means surrounding said upper pulley means for driven rotation thereby;

lower pulley means spaced along said path of advance and beneath said upper pulley means spaced along said path of advance and beneath said upper pulley means, the other of said belts surrounding saidlower pulley means for driven rotation disc means. 

1. A method of sealing a comestible article within a partially closed heat-fusible bag comprising the steps of: subjecting an open end portion of said bag to suction pressure for partially evacuating said bag; directing positive air pressure against an outer portion of said open end portion for collapsing said end portion; compressing said end portion for further depleting air from within said bag and for maintaining closure of saiD end portion; and heating a relatively narrow portion of said end portion for substantially simultaneously fusing said closed end portion and severing an outer portion therefrom.
 2. The method of claim 1 wherein compressing said end portion comprises the step of: applying positive pressure to opposite sides of said closed end portion to partially collapse said end portion and maintain said opposite sides in closed position.
 3. The method of claim 1 wherein heating said narrow portion comprises the steps of: supporting one of opposite sides of said end portion; and substantially simultaneously applying a heated member to the other of said opposite sides urging said opposite sides together under pressure sufficient to fuse said opposite sides and to sever an outer portion therefrom.
 4. A method of sealing a comestible article within a partially closed heat-fusible bag comprising the steps of: advancing said article within said bag along a path of advance with an open end portion of said bag advancing along a support means; applying air pressure against a top portion of said open end portion and substantially simultaneously withdrawing air from within said bag through said end portion to collapse said end portion into closed engagement; advancing said article with said closed end portion passing between a compression means for further depleting air from within said bag and for maintaining said end portion in closed engagement; and thereafter advancing said article with said closed end portion passing between cooperating portions of a heat sealing means for fusing said closed end portion and for substantially simultaneously severing an outer portion from said fused end portion.
 5. The method of claim 4 wherein advancing said article comprises the steps of: advancing said article within said bag along a conveyor means and supporting a bottom portion of an open end portion of said bag at a level between top and bottom sides of said article within said bag.
 6. The method of claim 4 wherein applying air pressure against a top portion of said open end portion and withdrawing air from within said bag comprises the steps of: directing a flow of air against said top portion urging said top portion toward a bottom portion of said open end portion and simultaneously directing a flow of air away from said top and bottom portions for drawing said top and bottom portions into closed engagement.
 7. The method of claim 4 wherein advancing said article with said closed end portion passing between a compression means comprises the step of: advancing said closed end portion between upper and lower flights of a pair of cooperating endless belts for compressing said closed end portion to further deplete the air from within said bag and maintain said end portion in closed engagement.
 8. The method of claim 4 wherein advancing said article with said closed end portion passing between cooperating portions of a heat sealing means comprises the step of: advancing said closed end portion between the outer peripheries of a pair of cooperating sealing discs of which one disc of said pair supports one side of said closed end portion and the other is heated for urging an opposite side of said closed end portion into fused engagement with said one side, said sealing discs simultaneously severing an outer portion of said closed end portion from said bag.
 9. The method of claim 4 further including the step of maintaining the temperature of said heat sealing means between selectable limits.
 10. Apparatus for sealing a comestible article within a partially closed heat-fusible bag comprising in combination: air pressure means including a blower having an exhaust structure for directing a flow of air against one of said opposite sides and an intake structure adjacent said open end portion for withdrawing air from within said bag, said exhaust structure and said intake structure cooperatively urging said opposiTe sides into closed contact; compression means for receiving said closed end portion and for further compressing said end portion to deplete additional air from within said bag through said end portion while maintaining closed contact thereof; and heating means for receiving said closed end portion and for substantially simultaneously fusing said opposite sides and severing an outer portion of said end portion from said bag.
 11. The apparatus of claim 10 wherein said compression means comprises: a pair of rotatable endless belt means including opposed parallel flights for receiving said closed end portion and further compressing said end portion to deplete air from within said bag.
 12. The apparatus of claim 10 wherein said heating means comprises: a pair of rotatable disc means one of which is heated for pressing said opposite sides against the other of said disc means to fuse said opposite sides and sever a portion of said end portion from said bag.
 13. Apparatus for sealing a comestible article within a partially closed heat-fusible bag comprising in combination: advancing means for advancing said article within said bag along a path of advance including support means for supporting an open end portion of said bag along said path; air pressure means adjacent one side of said advancing means for applying air pressure against a top portion of said open end portion and for withdrawing air from within said bag through said end portion to collapse opposite sides of said end portion into closed contact against said support means; compression means adjacent said one side of said advancing means and downstream from said air pressure means for further compressing said opposite sides to deplete additional air from within said bag while maintaining closed contact of said opposite sides of said end portion; and heat sealing means adjacent said one side of said advancing means and downstream from said compression means for fusing said opposite sides and for simultaneously severing an outer portion of said end portion from said bag.
 14. The apparatus of claim 13 wherein said advancing means comprises: conveyor means movable along said path of advance for moving said article past said air pressure means, said compression means, and said heat sealing means, said support means comprising a flange means extending along one side of said conveyor means for supporting a bottom portion of said open end portion between top and bottom sides of said article within said bag.
 15. The apparatus of claim 13 wherein said air pressure means comprises: blower means including exhaust means overlying said top portion for directing a flow of air against said top portion and intake means laterally adjacent a bottom portion of said open end portion for producing suction within said bag and, together with said flow of air, for urging said top and bottom portions into closed contact.
 16. The apparatus of claim 13 wherein said compression means comprises: a pair of rotatable endless belt means including opposed parallel flights in substantial alignment with said support means for compressing said end portion therebetween to deplete air from within said bag and to maintain said opposite sides in closed contact during advancement of said article to said heat sealing means.
 17. The apparatus of claim 13 wherein said heat sealing means comprises: a pair of rotatable disc means having tangential surfaces in substantial alignment with said end portion along said path of advance, one of said disc means being heated for pressing said opposite sides against the other of said disc means under pressure sufficient to fuse said opposite sides and simultaneously sever an outer portion of said end portion from said bag.
 18. The apparatus of claim 13 wherein said compression means and said heating means comprise: a pair of rotatable endless belt means including opposed parallel flights in substantial alignment with said support meaNs; upper pulley means spaced along said path of advance adjacent said advancing means, one of said belt means surrounding said upper pulley means for driven rotation thereby; lower pulley means spaced along said path of advance and beneath said upper pulley means spaced along said path of advance and beneath said upper pulley means, the other of said belts surrounding said lower pulley means for driven rotation thereby; upper disc means forming part of said upper pulley means at a downstream end thereof, said upper disc means including selectively controllable heating means for heating said upper disc means to a temperature between selectable limits; and lower disc means forming part of said lower pulley means at a downstream end thereof, said lower disc means supporting said opposite sides of said end portion during fusing of said end portion by pressure between said upper disc means and said lower disc means. 